When patients think about cancer, most jump straight to genetics and lifestyle — smoking, sunlight, family history, processed food. An often-overlooked category deserves more airtime: infectious causes. A BBC report summarising a large global analysis highlighted this: about 17% of cancers worldwide are caused by infections.
The main offenders
Four infections account for most of the infection-related cancer burden:
- Human papillomavirus (HPV) — cervical, oropharyngeal, anal, penile, vulvar, and vaginal cancers. Preventable with vaccination.
- Hepatitis B and C viruses — liver cancer. Hepatitis B preventable with vaccination; hepatitis C now curable with direct-acting antivirals.
- Helicobacter pylori — stomach cancer and MALT lymphoma. Detectable and treatable with antibiotic combinations.
- Epstein-Barr virus (EBV) — nasopharyngeal carcinoma, Burkitt lymphoma, Hodgkin lymphoma — particularly relevant in Southeast Asia.
The burden falls disproportionately on lower- and middle-income countries, where screening and vaccination programmes reach fewer people, and where infections that were once common childhood exposures remain prevalent into adulthood.
Why this matters for Malaysia
Southeast Asia carries a meaningful share of the world’s infection-related cancer burden:
- Hepatitis B remains a significant public health issue despite strong vaccination programmes. Chronic hepatitis B carriers need monitoring for liver cancer.
- HPV causes most cervical cancer and a rising share of head-and-neck cancer. Vaccination (boys and girls) and screening both matter.
- H. pylori infection is widespread and often asymptomatic. Testing and eradication meaningfully reduce long-term gastric cancer risk, especially in patients with a family history.
- Nasopharyngeal carcinoma (EBV-associated) has particularly high incidence in ethnic Chinese populations in the region.
What patients can do
Three concrete steps that reduce infection-related cancer risk:
- Vaccinate. HPV and hepatitis B vaccines are both genuinely protective. If you or your children haven’t been vaccinated, it’s worth asking.
- Screen when appropriate. Cervical cancer screening (Pap smears or HPV testing), hepatitis B antigen testing if you’ve never been tested, and H. pylori testing if you have recurrent dyspepsia or a family history of gastric cancer.
- Treat what you find. Chronic hepatitis B can be suppressed; hepatitis C can be cured; H. pylori can be eradicated. None of these are things to “live with” once identified.
The framing that matters here: a meaningful slice of cancer risk is not fixed at birth. It’s modifiable, and the tools are available.